AJ06GT

Okay, you guys may have never heard of this before, but I figured I'd throw this out there since I'm going to be replacing my thermostat while I change my hoses and coolant, but my dad had told me about hearing of some guys drilling a small hole in their thermostat to ensure that no air pocket could form under the thermostat and throw it off. He doesn't know if this is just an oldtimer type trick that some people do, or if it maybe was just because of issues on that particular engine. Just figured I'd throw the question out here to you guys and see if any of you have heard this before and if you recommend it or not. If no one has heard of it I wont do it, but I'll give a little while for some opinions while I drain the system and get the old hoses off.

AJ06GT

I'm gonna take that as a no.

BraMas

Makes no sense to me. I would just put it in the way it comes.

Tac2cul

+1

2000GT4.6

+2

oxfordgt

Actually alot of OEM thermostats come with a hole drilled in it.

blstoff

if you drill holes it will just take alittle longer to warm up . probably wont run any cooler , maybe a little . might as well get a 160* or 180* tstat .

AJ06GT

Actually when I got the factory thermostat off it has basically the same thing, but a little fancier. It has a hole, but it also has a small piece of metal in it to act as a one way valve. I didn't bother though. I figure if the new thermostat doesn't have one then it must not be a big deal.

undecided.steve

Actually like the other guy said, a lot of new thermostats come with a hole/rivet allready in them. What this does is save your engine should the thermostat fail closed or should you get an air pocket trapped there. You'd be amazed how much coolant can get through that little hole when it is the only way for the coolant to pass through
The downside is it takes a little longer to heat up and depending upon the size of the hole, you may not reach full operating temperature.

My Caprice has had a very slight manifold leak on the exhaust side which blows a minute amount of exhaust gas into the coolant.
It's been doing this for 200,000 miles or more and doesn't harm anything EXCEPT, the first start up of the day may or may not cause the temp gauge to head sky high until the gases trapped under the thermostat get hot enough to open it.

It also doesn't happen every time and it drove me crazy for about 3 months until I read about it being a common problem with some cars.

I solved the problem by drilling a very small hole on the edge of the thermostat and it has worked fine ever since.

Car is now approaching 400,000 miles on original engine and tranny and runs like Swiss watch.

Colorado_Mustang

It is an old school trick to drill a small hole in the top of the t-stat. It's primarily to help burp the engine since an air bubble can quickly destroy a block or head. It also allows a little more coolant flow, which can be beneficial.

I typically have a 1/8" hole in the t-stats in my older cars. I left the stocker in my 03 alone after swapping in a 180* stat for a short period of time.